Global NEST Journal

In this study the efficiency of crystal violet dye removal from aqueous solutions using lilac tree leaf powder as adsorbent material was tested. After adsorbent surface analysis by SEM and FTIR technics, the influence of six controllable factor on dye adsorption process was assesses using a L27 Taguchi experimental design. The optimum adsorption conditions and the controllable factors significance were established by evaluation of signal-to-noise ratio (S/N). ANOVA analysis revealed the percentage contribution of each factor in crystal violet removal. Langmuir isotherm and pseudo-second order kinetic model characterized the process and the maximum adsorption capacity was higher than other similar adsorbents previously used in literature. The thermodynamic parameters reveal a favorable, spontaneous and endothermic adsorption based on physisorption mechanism.

The coronavirus (COVID-19) is a threat to public health and caused several social, environmental, and economic problems. During the lockdown in different countries, waste generation has been significantly increased due to the high consumption of packaged food and increase the order of food via online and takeaway. This paper aims to investigate the impact of COVID 19 lockdown on food consumption and the subsequent change in waste generation in Oman. A quantitative research methodology was applied for this study using an online survey during the COVID 19 lockdown. The survey collected information on demographic data, awareness and attitudes toward food purchase behaviour, household food expenditure, and waste generation. The results show that 57.6% of the respondents believed that their food purchasing during the lockdown was increased as compared to before the lockdown. The main reason for increasing the food purchasing was the change in consumers behaviour and cooking more in households during the lockdown. This increase led to the increase in waste generation. One of the main reasons for the increased waste generation during the lockdown was the fact that people have spent more time at home. It was found that food waste and plastic packages were the highest increase (72% and 55%, respectively). These two types of waste are followed by cans and glass bottles with an increase of 68%. Other types of waste such as medical waste, electrical and electronic waste, and paper waste have shown no significant change in waste generation during the lockdown. Overall, this study provides useful information to further promote household food waste prevention behaviour, outlasting the COVID-19 crisis. The results from this study can be used by waste management and municipal utilities on consumption behaviour during emergency situations.

Numerical simulation was conducted to assess the impact of dust emission on typical environmental sites in Jinan City. The CALPUFF model was applied to five simulation scenarios. The results showed that dust emission had a significant impact on air quality in Jinan. The impact of dust emission on the average concentration of PM10 at 15 monitoring sites was 19.8 μg/m3, accounting for 14.9% of the annual total. The impact of dust emission on the average concentration of PM2.5 was 5.2 μg/m3, accounting for 8.1% of the annual total. Adoption of yellow warning measures in the emission reduction scenarios had insignificant environmental effects due to unfavorable meteorological conditions. Compared with the baseline scenario, the average concentrations of PM10 and PM2.5 decreased by 13.6% and 1.9%, respectively. After adoption of orange and red warning measures, the impact of site dust emission on air quality at the monitoring site was reduced significantly. Significant environmental effects were achieved after all construction sites within a 2-km radius of the monitoring site were closed. Compared with the baseline scenario, the average concentrations of PM10 and PM2.5 were reduced by 45.5% and 42.3%, respectively. The results showed that under adverse meteorological conditions, higher-level warning measures should be undertaken to reduce the impact of site emissions on environmental quality. Considering the economic and social effects of emission reduction, temporary construction stoppage within 2 km of the monitoring site is a feasible plan that is in accordance with the goals of comprehensive environmental management.

The Maluku Islands (henceforth MI) are situated in the northeastern Indonesia. Ocean region off the central MI is pivotal as it provides a course for the Indonesian Throughflow (ITF) through the Lifamatola passage. However, sea surface dynamics off the central MI is unknown until recently due to inadequate measurements. The current fact motivates the present study to decipher the coastal wind variability off the central MI and its effect on the sea surface by analysing long-term datasets (2007-2019) of satellite-derived sea surface wind, sea surface temperature (SST), and surface chlorophyll-a concentration. Possible influence of extreme climate events of the 2015 El Niño-Southern Oscillation (ENSO) and the 2019 Indian Ocean Dipole (IOD) on all oceanographic parameters was also examined. Results show that the prevailing southeasterly winds over the central MI induce SST cooling and phytoplankton bloom. Correlation analysis revealed that the ENSO and IOD play significant roles in defining spatial distribution of the coastal wind, SST, and phytoplankton bloom in the research area. In addition, the anomaly analysis exhibits distinct oceanographic features during the climate extreme events of 2015 and 2019. Collectively, results of the present research highlight the importance of coastal wind variability and extreme events in shaping the ocean surface characteristics and perhaps regional fisheries production.